Understating the Mitigation Challenge, IEA 2008November 13th, 2008
Posted by: Roger Pielke, Jr.
Last spring along with Tom Wigley and Chris Green we published an article in Nature (PDF) arguing that the IPCC had underestimated the magnitude of the mitigation challenge. Today I’d like to illustrate how the IEA’s World Energy Outlook, published yesterday, also dramatically underestimates the magnitude of the mitigation challenge.
The figure below is taken from the IEA’s publicly-available packet of key graphs (here in PDF). I have annotated it as follows to illustrate how the IEA has significantly underestimated the mitigation challenge.
A. The IEA’s first understatement involves incorrect data about the size of actual global emissions. According to the Global Carbon Project they were about 31.5 GtCO2 in 2007.
B. This curve illustrates what happens if you simply move up the IEA curve to the actual 2007 value, preserving the IEA’s average rate of growth in CO2 emissions of 1.4% per year. The choice of 1.4% per year is puzzling because, as the Global Carbon Project notes, CO2 emissions have been increasing by more than 3.0% per year in recent years. Even with a global economic slowdown, there would seem to be a real possibility that actual emissions growth will occur at a rate faster than 1.4% per year.
C. This curve shows what would happen if CO2 emissions increase at the same rate as energy demand in the IEA reference scenario, which is 1.6% per year, to 2030.
D. And this curve shows what would happen in CO2 emissions increase at a rate of 2.0% per year to 2030. Experience of the current decade shows that even faster rates of growth are possible over extended periods, so this is by no means an upper limit.
You should conclude from this exercise that it is possible, even probable, that the IEA has underestimated the mitigation challenge by a very large amount. Consequently, the IEA’s cost estimates depend upon first assuming a very low rate of growth for carbon dioxide emissions, starting from a misleading baseline. This will have the effect of making the challenge look smaller and less costly (and yet, even in the IEA scenarios the challenge is huge and expensive).
I cannot help but think that mitigation policies are poorly served by getting the scope of the challenge wrong at the outset. I suspect we are dooming them to failure.